Method of waterproofing fibrous products



Patented Jan. 24, 1933 UNITED STATES PATENT OFFICE GMBGE TAKES HANSON, OI HAWKESBUBY, ONTARIO, CANADA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO HANSON GBEHICAL COMPANY,

CORPORATION 01' NEW JERSEY OF MONTCLAIR, NEW JERSEY, A.

METHOD OF WATERPROOFING FIBBOUS PRODUCTS Io Drawing. Original application filed. July 8, 1928, Serial No. 121,261. Divided and this application filed April 25, 1927.

This invention relates to improvements in methods of waterproofing fibrous products, and the objects of the invention are to provide an efiective method of waterproofing such 5 products during the process of manufacture thereof.

The method makes use of an emulsion of a water repellent substance prepared as described in my co-pending application Serial No. 121,261, filed July 8th, 1926, of which the present application is a division.

In emulsions of the character to which this invention refers, it is desirable that the emulsions when formed, should be freely diluted with water, and to this end that the individual part1cles of wax should be thinly coated with the emulsifying medium so that thelr bulk will not be unduly increased, and the particles remain in discrete form without any tendenc to tackiness. I have found that it is possi le to form a thin but SllifiClGIlt coatin about the particles of wax by forming a ge? in the emulsified mixture rather than by adding a pre-formed emulsified agent thereto.

Such a gel may be formed by a variety of compounds as for example by combming a water soluble acid salt with a silicate, the reacting of which is preferably caused to take place while being mixed with the molten wax while the whole mass is agitated and/or in rapid motion.

Of water soluble electrolytes which may be used, I may mention magnesium chloride,

magnesium sulphate, aluminum sulphate, calcium chloride, or other electrolytes of a similar nature. Sodium silicate maybe conveniently used as the silicate to form the gel or latinuous coating material. The meth- 0d is applicable to wax which may be animal, mineral or vegetable wax, as well as to the emulsification of these ingredients with themselves or with wax.

' In practicing the method, the wax or other water repellent material is melted and mixed Serial No. 186,801.

with Water containing in solution the sodium silicate. The solution of an electrolyte or electrolytes is then added, of the character above described, and the mixture stirred, the temperature being above the melting point of wax or water repellent substance, whereby the gel formed in the mixture will form an insoluble encysting coating about the particles of wax for other water repellent substance to maintain the wax or water repellent substance in discrete form when the mixture cools.

The following may be taken as practical examples of methods of making the emul- Slon: Example I 100 pounds of Montan wax (a water repellent substance) is melted and 8 pounds of sodium silicate (a water soluble substance) is added in 120 pounds of water; this solution is heated to about 10 above the melting point of Montan wax; the mixture of melted Montan wax and the solution of sodium silicate is then rapidly stirred and 4 pounds of magnesium sulphate (a Water soluble material) dissolved in 40 pounds of water is added. An encysting gel is immediately formed about the particles of Montan wax, keeping them from coalescing together when the mixture cools. It will be seen that by this means the wax is maintained in a finely divided state and in a condition which enables it to be readily disseminated through any material with which it is to be used.

Ewample ll P61 cent 2 1,sos,oso

Emple III com'" ition while dispersm the water-re pelle ft substance, and int ucing the dis- PM persion into paper stock. mdm 2. The method as set forth in claim 1 sum. 0 WNW-(65% of the wherein the dispersion iscoagulated... W 3. The method of wate roofing paper of total whichfcomprises ffrming a ogeilllnuxz ture o a silica e -enc water-re Glueto of substance and ingroducmg the m into pa- 121p enolbased on glue) per stock. u

4. Th thod f fibrous of is added to melted product: which con ipri s e s f dxn z a m the alum. is added sion of a gel encysted water repellent subafter thorough agitation. Working temstance and glue and introducing the m 4 M 170 E into aper stozhkd f .9

k [7 6. 0 me o o waterproo paper E Per cent which comprises forming a dispefir si on con- Plnfin taining an encysted water repellent substance Montan melted with W 7- nd glue, and introducing the dispersion into Silicate o sodaplus(65% of the total we Alumplus (86% of the total water) 1.85 Water 58.0

as The silicate of soda is added to the melted wax in a disin tor and the alum isadded after thorough agitation. Working temperature 170 F.

The mixture or emulsion may be used to so waterproofingaper or taxtilematerials. {1; w roo e mixture may add fintgo the with or without tswaterroo ts,an coagula tingagen p Alum, ior instance, may be added to comsapleteany cct to the peculiar or on Wax particle which ma to the method of forming t wax disper- 40 sion) so great a proportion of alum as is customarily employed with, for example, resin size neednotbeusedinthepracticeofthe preferred form of the present invention.

As many changes could be made in the above construction and many apparently widely different embodiments of my invention, within the scope of the claims constructed without d from the spirit or scope thereof, it is intended that all matso ter contained in the accompanying specification shall be interpreted as illustrative and not in a sense.

In companion application 186,608, filed April 25, 1927, entitled Fibrous products to there is claimed paper products produced the paper p compositions containm w during encasemmt or on of those particles by t1Ineaus of gels formed by double decomposi- What I claim as mfy invention is: 1. The method 0 waterproofing paper which comprises encasing a water-resistant 66 en with a gel formed by double depaper stock.

6. The method as dligreindescrihetg which comprises ormmg a person con uunga water repellent substance and glue, and mtroducing the same into paper stock.

7. The method as herelndescribed which comprises introducing into paper stock, a dispersion containing a water repellent substance aud glue.

8. The methgg as hereindescribed which comprises intr ucing into paper stock, a dispersion containing a water refellent substance glue, and a reservative or the glue.

9. method 0 producing 'wa products which comprises agitating an aqueous solution of an electro yte with a water repellent substance to break up the water repellent substance into finely divided particles carried in said aqueous solut'mn, addin a second electrolyte reactive with the first ectrolyte to form a recipitated upon the particles of the fin y divided wa repellent substance whereby the articles of finely divided water repellent su ce become encysted in the precipitated gel and dispersed thereby in the aqueous medium, and incorporating said dispersion with paper 10. The rocess of forming waterproof products hich comprises agitating an aqueous solution of an electrolyte with a wax to break up the wax into finely divided particles carried in said aqueous solution, addin a second electrolyte reactive with the first e ectrolyte to form a precipitated gel u n the particles of the finely divided wax w ereby t e particles of wax become encysted in the precipitated l and dispersed thereby in the aqueous m ium, and inco said dils gersion with aper stock.

11. e gcooess o preparing waterproof products w h comprises agitating an aqueous solution of an el with a water repellent substance to b u the water repellent substance into finely ivided particles carried in said aqueous solution, adding a 0 second electrolyte reactive with the first electrolyte to form a preci itated gel upon the particles of the finel ivided water repellent substance whereb fi the particles of nely divided water repe ent substance become encysted in the precipitated gel and dis persed thereby in the aqueous medium, and incorporating said dispersion with paper stock, and coa ulating said dispersion in the paper stock a ter incorporation therewith.

12. The process of preparing waterproof products which comprises simultaneously dispersing a water repellent substance in an aqueous medium while encysting the dispersed particles of the water repellent substance by means of'a gel formed by double decomposition, incorporating said dlspersion with paper pulp.

In witness whereof I have hereunto set my hand.

GEORGE JAMES MANSON. 

